Rodriguez Guyot (a flat-topped
submarine mountain) is
located about halfway up the continental rise, offshore Santa Barbara. It
is structurally similar to Guide, Gumdrop, Pioneer, and Davidson
Seamounts, all located farther north at the base of the continental slope
about 150 km off the central California coast.

These submarine
volcanoes are morphologically distinct from typical ocean island volcanoes
and seamounts in having complex, elongated structures with a distinctive
northeast to southwest orientation common to many other volcanic edifices
near the continental margins of Southern and Baja California (Atwater and
Severinghaus, 1989; Lonsdale, 1991). They are aligned parallel to, and
perhaps on top of, abandoned mid-ocean spreading ridges. Magnetic
anomalies outboard from Rodriguez are Chron 5E indicating it is located on
19 million year old ocean crust (Atwater and Severinghouse, 1989). Rocks
recovered from Rodriguez Guyot are alkalic basalt and hawaiite (Davis et
al., 1995; and submitted) and have been dated by Ar-Ar techniques that
indicate that the volcano is 10 to 12 million years old (Davis et al.,
1995; and submitted). These seamounts, including Rodriguez, are the
product of intraplate oceanic volcanism unrelated to hot spots (Davis et
al., submitted).

Rodriguez Guyot rises about 1,675
meters
above the surrounding seafloor to a minimum water depth of 650 meters.
Its calculated volume of 205 km3 is probably a minimum value
because the survey did not cover the lowermost slopes (Davis et al.,
submitted). The NE fabric is
less well-defined than for most of the other seamounts, and large volcanic cones are
also present. The largest of the cones is 700 m tall and 2.2 km across at the
base and has a volume of about 2.6 km3. The sediment drape on
the lower flanks of the volcano has slumped, particularly on the southwest
flank. Another slump on the west flank has a field of blocky debris at its
base, suggesting that the volcanic basement also slumped.

MBARI provides these data "as is", with no warranty, express or implied, of the data quality or consistency. Data are provided without support and without obligation on the part of the Monterey Bay Aquarium Research Institute to assist in its use, correction, modification, or enhancement.